Let's improve D's exceptions

[Adam D. Ruppe via Digitalmars-d]

On Friday, 15 May 2015 at 09:23:12 UTC, Jacob Carlborg wrote:
> So why isn't data members used more, because of the boilerplate 
> to create a new subcalss?

Yeah, I think so. A new exception subclass has to write out the 
long constructor signature, forward it, add the data members, 
write code to set them, and at least write code to add them to 
the toString (which itself has a long signature and needs a lot 
of string formatting tedium).

That's a fair amount of code to write, especially compared to new 
Exception("foo " ~ to!string(value)) right there inline when it 
comes up.


But with reflection we can really simplify it to the point where 
writing class Foo : Exception { int value; mixin ExtendException; 
} becomes less of a hassle, or we could even extend a hierarchy 
right inline like raise!SomeException(variadic, arguments).